I totally agree about Arianwen. I think the idea of it is better than the reality. I'm pronouncing it with four syllables. Is that correct? The first part is pretty close to Aryan, which makes me think of Nazis, which isn't cool at all.
I don't like Faye as a mn with it. But I don't like the name Faye with any name, so don't worry about me. You'd definitely need something super simple and short with a first name like that!
Octavia is okay, nms, but okay. I think Octavia Evelyn sounds really pretty. The v's in each name give it a nice continuity.